The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 125.77 annum (million years ago) and 121.4 ± 1.0 Ma[Cohen, K.M., Finney, S.C., Gibbard, P.L. & Fan, J.-X. (2023; updated) The ICS International Chronostratigraphic Chart. Episodes 36: 199-204.] (Historically, this stage was placed at 129.4 million to approximately 125 million years ago[See Gradstein et al. (2004) or the online geowhen database (link below)]
Stratigraphic definitions
The original type locality for the Barremian Stage is in the vicinity of the village of Barrême, Alpes-de-Haute-Provence, France.
Henri Coquand defined the stage and named it in 1873.
The base of the Barremian is determined by the first appearance of the Spitidiscus and Spitidiscus vandeckii. The end of the Barremian is determined by the geomagnetic reversal at the start of the M0r chronozone, which is biologically near the first appearance of the ammonite Paradeshayesites.
Regional equivalents
The Barremian falls in the
Gallic epoch, a subdivision of the
Cretaceous that is no longer used by the ICS. It overlaps the lower part of the stage, which is sometimes used in western European stratigraphy. In
North America, the late
Coahulian and the early
Comanchean correspond to the Barremian. In
New Zealand, it falls within the
Mokoiwian, and in
Japan it corresponds to the late
Aritan.
Subdivision
The Barremian is often subdivided into two substages or subages, Lower/Early and Upper/Late Barremian.
In the Tethys Ocean, the Barremian stage contains eleven ammonite :
Notes
Literature
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(1907): Le Barrémien supérieur à faciès Urgonien de Brouzet-lès-Alais (Gard). Mémoires de la Société Géologique de France, Paléontologie 15(37): 5-42.
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; (2004): A Geologic Time Scale 2004, Cambridge University Press.
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(2006): Assessment of diachronism of biostratigraphic boundaries by magnetochronological calibration of zonal scales for the Lower Cretaceous of the Tethyan and Boreal belts. Doklady Earth Sciences 409(6): 843-846.
External links
